Lifetime Parameters Research Articles

Precision investigations of clock transitions and metastable lifetimes in highly charged Te-like ions

This study utilizes the multi-configuration Dirac-Hartree-Fock method to accurately calculate the lifetime and atomic parameters for the metastable state S01 of the 5s25p4 configuration, pertinent to clock transitions in Te-like highly charged ions. We systematically account for Valence–Valence, Core-Valence, and Core-Core electron correlations, alongside Breit interaction and quantum electrodynamics effects. Addressing the contingency problem regarding the lifetime of metastable state S01 of Xe2+ ion, as highlighted by E.Träbert (Phys. Scr. 85, 048101, 2012, https://doi.org/10.1088/0031-8949/85/04/048101) and K.G.Bhushan et al. (Phys. Rev A, 62, 012504, 2000, https://doi.org/10.1103/PhysRevA.62.012504) in early experiments and theories, we present theoretically calculated lifetime results. Our reasonable electron correlation model predicts a lifetime of 4.44 ms, which agrees with the experimentally measured lifetime of 4.46 ± 0.08 ms. Furthermore, we investigate the energy level crossing between 3P0 and 3P1 in Te-like systems near atomic number Z=52, where 3P→03P2 transition serves as a clock transition. We have calculated the atomic parameters related to the clock transition and hope that these results will provide valuable insights for the development of future highly charge ion clocks.

Two sunspot group populations and Gnevyshev-Waldmeier rule

Based on the materials of the Royal Greenwich Observatory catalog, the study of two different sunspot group populations continued: LLG – large long-lived, and SSG – small short-lived groups. The task of achieving a higher accuracy of the population separation parameter than before (Nagovitsyn & Pevtsov 2016, 2021) is being solved. A procedure for randomizing the lifetimes of sunspot groups observed once a day is proposed, which allows for statistical studies to achieve a higher time resolution. The form of the Gnevyshev-Waldmeier Rule is taken, which linearly connects the logarithm of the logS area and the lifetime of the sunspot group LT (over limited time intervals). It is shown that it has coefficients significantly different for SSG and LLG populations. The range of values of the group lifetime parameter separating the populations was found as LT∗=4.75±0.53 days, which is in agreement with the threshold values obtained earlier for the number of days of sunspot group observation: mSSG⩽5 days and mLLG>5 days. It is shown that the parameters of the bilognormal distribution of the sunspot group areas, obtained from their common grouped sample statistically by Levenberg–Marquardt method and with a preliminary division into lognormal distributions by lifetime, correspond to each other. It was clarified that, with an accuracy of up to a tenth of a day, the SSG population corresponds to the lifetimes of groups ⩽4.6 days, and the LLG population corresponds to times ⩾4.7 days. The results obtained make it possible to study various physical properties of SSG and LLG populations independently of each other in order to compare them and study their nature.

Different Statistical Inference Algorithms for the New Pareto Distribution Based on Type-II Progressively Censored Competing Risk Data with Applications

In this research, the statistical inference of unknown lifetime parameters is proposed in the presence of independent competing risks using a progressive Type-II censored dataset. The lifetime distribution associated with a failure mode is assumed to follow the new Pareto distribution, with consideration given to two distinct competing failure reasons. Maximum likelihood estimators (MLEs) for the unknown model parameters, as well as reliability and hazard functions, are derived, noting that they are not expressible in closed form. The Newton–Raphson, expectation maximization (EM), and stochastic expectation maximization (SEM) methods are employed to generate maximum likelihood (ML) estimations. Approximate confidence intervals for the unknown parameters, reliability, and hazard rate functions are constructed using the normal approximation of the MLEs and the normal approximation of the log-transformed MLEs. Additionally, the missing information principle is utilized to derive the closed form of the Fisher information matrix, which, in turn, is used with the delta approach to calculate confidence intervals for reliability and hazards. Bayes estimators are derived under both symmetric and asymmetric loss functions, with informative and non-informative priors considered, including independent gamma distributions for informative priors. The Monte Carlo Markov Chain sampling approach is employed to obtain the highest posterior density credible intervals and Bayesian point estimates for unknown parameters and reliability characteristics. A Monte Carlo simulation is conducted to assess the effectiveness of the proposed techniques, with the performances of the Bayes and maximum likelihood estimations examined using average values and mean squared errors as benchmarks. Interval estimations are compared in terms of average lengths and coverage probabilities. Real datasets are considered and examined for each topic to provide illustrative examples.

Multispectral label-free in vivo cellular imaging of human retinal pigment epithelium using adaptive optics fluorescence lifetime ophthalmoscopy improves feasibility for low emission analysis and increases sensitivity for detecting changes with age and eccentricity.

Adaptive optics fluorescence lifetime ophthalmoscopy (AOFLIO) provides a label-free approach to observe functional and molecular changes at cellular scale in vivo. Adding multispectral capabilities improves interpretation of lifetime fluctuations due to individual fluorophores in the retinal pigment epithelium (RPE). To quantify the cellular-scale changes in autofluorescence with age and eccentricity due to variations in lipofuscin, melanin, and melanolipofuscin in RPE using multispectral AOFLIO. AOFLIO was performed on six subjects at seven eccentricities. Four imaging channels ( ) were used: 473/SSC, 473/LSC, 532/LSC, and 765/NIR. Cells were segmented and the timing signals of each pixel in a cell were combined into a single histogram, which were then used to compute the lifetime and phasor parameters. An ANOVA was performed to investigate eccentricity and spectral effects on each parameter. A repeatability analysis revealed change in lifetime parameters in repeat visits for 532/LSC. The 765/NIR and 532/LSC had eccentricity and age effects similar to previous reports. The 473/LSC had a change in eccentricity with mean lifetime and a phasor component. Both the 473/LSC and 473/SSC had changes in eccentricity in the short lifetime component and its relative contribution. The 473/SSC had no trend in eccentricity in phasor. The comparison across the four channels showed differences in lifetime and phasor parameters. Multispectral AOFLIO can provide a more comprehensive picture of changes with age and eccentricity. These results indicate that cell segmentation has the potential to allow investigations in low-photon scenarios such as in older or diseased subjects with the co-capture of an NIR channel (such as 765/NIR) with the desired spectral channel. This work represents the first multispectral, cellular-scale fluorescence lifetime comparison in vivo in the human RPE and may be a useful method for tracking diseases.

Recognition of multi-component compounds based on occurrence time of secondary crest in the fluorescence lifetime attenuation curve

Fluorescence lifetime is the main characteristic parameter of fluorescence. It is a widely used to draw fluorescence lifetime attenuation curves and to fit fluorescence lifetime parameters by using gated detection methods to identify the species of substances. However, the fluorescence attenuation of each fluorophore in a multi-component compound interferes with one another, affecting the accuracy of identification. In this paper, we propose a method to accurately identify substances by using the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve based on the principle of gated detection to measure the fluorescence lifetime. Furthermore, we design a fluorescence lifetime imaging measurement system and select the same areas of interest in the images for analysis and comparison. The average lifetime of the fluorescence and the occurrence time of the secondary crest are considered as the characteristic parameters. We use five commercially available motor engine oils as the experimental samples and compare the recognition performance of different kernel functions based on a support vector machine (SVM). The radial basis kernel function presents the best performance in terms of recognition accuracy and speed. The recognition rates of the SVM model with the average fluorescence lifetime and the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime as a feature vector are 76.24% and 74.65%, respectively. The recognition rate of the SVM model which combines them as feature vectors reaches 91.88%. The experimental results demonstrate that the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime can be employed as the basis for substance identification in the analysis of the fluorescence characteristics of multi-component compounds, whose recognition accuracy is similar to the average fluorescence lifetime parameter. Moreover, the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve can be implemented to identify multi-component compounds when it is used as a characteristic parameter.

System Metamodeling of Open-Ended Evolution Implemented with Self-Modifying Code

Having a model and being able to implement open-ended evolutionary systems is important for advancing our understanding of open-endedness. Complex systems science and the newest generation high-level programming languages provide intriguing possibilities to do so. Here, some recent advances in modeling and implementing open-ended evolutionary systems are reviewed (an earlier and shorter version was presented at [1]). Then, the so-called allagmatic method is introduced as a computational framework that describes, models, implements and allows interpreting complex systems using system metamodeling. Based on recent advances, the model building blocks evolving entities, entity lifetime parameter, co-evolutionary operations of entities and environment and combinatorial interactions are identified to characterize open-ended evolutionary systems. They are formalized within the system metamodel, providing a formal description of an open-ended evolutionary system. The study further provides a self-modifying code prototype in C# and guidance to create code blocks for an intrinsic implementation of open-ended evolutionary systems. This is achieved by controlling the self-modification of program code within the abstractly defined building blocks of the system metamodel. It is concluded that the identified model building blocks and the proposed self-modifying code provide a promising starting point to model and implement open-endedness in a computational system that potentially allows us to interpret novelties at runtime.

Statistical inference of a step-stress model with competing risks under time censoring for alpha power exponential distribution

Accelerated life testing in a reliability experiment allows test units to be under more stress than normal (expected). Step-stress tests are a subset of accelerated life tests that raise the stress levels at specific predetermined time periods to gather data on lifetime parameters more quickly than they would under normal operating settings. Additionally, there are frequently a number of risk factors connected to the root cause of a test unit failure (mechanical, electrical, etc.). In this article, we discuss the statistical inference of a step-stress model in the presence of time censoring assuming independent alpha power exponential distribution. The point estimates of the unknown scale and shape parameters of the various causes are determined using the maximum likelihood technique under the assumption of cumulative damage. We also go through creating confidence intervals for the parameters using asymptotic distributions and the parametric bootstrap approach. Extensive Monte Carlo simulations are used to evaluate the accuracy of the estimates and the performance of the confidence intervals, and finally, an example is used to explain the methods of inference presented here.

Two commodity queueing inventory system with random common lifetime, two demand classes and pool of customers

This paper analyzes a two-commodity perishable queueing inventory system with random common lifetimes commodity-wise, positive service time, and individual ordering policy. We have considered two types of customers: priority customers and non-priority customers. There is a buffer of finite capacity for the priority customers and a pool with infinite capacity made available for the non-priority customers. The arrival of these customers is occurred by two independent Poisson processes. The lifetimes of each of the commodities and service times follow independent exponential distributions. The matrix geometric approach is used to analyze the model's steady-state behavior and we computed various system performance measures. This article examines the effects of the common lifetime parameters on the measures of performance, such as average cycle time, the average number of reorders due to the realization of the common lifetime of commodities, etc. Also, a sensitivity analysis of the system parameters on the performance measures is carried out. Further, a cost function is constructed based on the performance measures, and its convexity is examined numerically.

RETRACTED: A 6U CubeSat Platform for Low Earth Remote Sensing: DEWASAT-2 Mission Concept and Analysis

This paper presents an in-depth analysis of DEWASAT-2, a 6U CubeSat designed for low Earth remote sensing applications. DEWASAT-2 is equipped with two payloads: a high-resolution camera for Earth observation and a spectrometer for detecting greenhouse gases. This paper describes the mission analysis and design of DEWASAT-2 as well as the link budget, power budget, and data budget. Additionally, the paper includes simulations and plots that illustrate the access times, lifetime, and other important parameters of the CubeSat. The outcomes presented in this article emphasise that DEWASAT-2 will contribute to fulfilling and enhancing various use cases of the Dubai Electricity and Water Authority (DEWA) network such as weather monitoring and forecasting and the detection of seawater salinity.

Structural Features, Emission Analysis, and Covalency Comparison of Neodymium Acylpyrazolone Complexes using Oscillator Strengths, Covalency and Judd‐Ofelt Parameters**

AbstractThree distorted square antiprismatic eight coordinated neodymium acylpyrazolone complexes were synthesized having the compositions [Nd(L1)3(H2O)(EtOH)] (NdL1), [Nd(L2)3(H2O)(EtOH)] (NdL2), and [Nd(L3)3(H2O)(EtOH)] (NdL3). The structure of all three complexes was examined using ESI‐mass, FT‐IR, and thermogravimetric methods. According to the single crystal analysis of NdL1, the complex was found eight‐coordinated (NdO8) with a distorted square antiprismatic geometry. A powder XRD pattern confirmed a similar structural arrangement of the other two complexes. In electronic absorption spectra, the transition 4G5/2←4I9/2, which is close to the centre of the visible spectrum (~17,500 cm−1), exhibits hypersensitivity, which stands out in stark contrast to the behaviour of many other typically weak and reliably unchanging, typical 4f–4f transitions. Through a comparative analysis of calculated oscillator strength, Judd‐Ofelt parameters, root mean square deviation, radiative lifetime and covalency parameters in various solvents, hypersensitivity, symmetry characteristics, and covalency have been thoroughly investigated. The promotion of 4f–4f electric‐dipole intensity has been found to be particularly successful with ethanol, pyridine, DMF, and DMSO. Utilizing Judd‐Ofelt Ω4 values and Hirshfeld analysis, long‐range secondary π⋅⋅⋅π stacking or H‐bonding interactions were investigated. The intensity of emission spectra, quantum yield, stokes shift, and antenna effect energy diagram was examined using solid‐state emission spectra.

Beamforming with modified steering vectors for jet noise source location

Prof. Krish Ahuja has a longstanding interest in jet noise source location. His work in this area is grounded in the idea that if the assumed source location is correct, then the sound should obey the inverse square law relative to that point and the phase should be constant along lines originating at that point. He applied this with, conceptually, one microphone in 1985 and two microphones in 1998. In 2006 he commissioned a beamforming system, Array 48, from OptiNav, Inc. His student, Nick Breen, used this to measure subsonic jet noise source location in detail. The NASA-Glenn Research Center also purchased an Array 48. In the current work, a jet noise data set measured by Gary Podboy using Glenn’s array in 2008 is revisited with a new beamforming algorithm, Robust Functional Beamforming, to further support Tam’s two-source model and Breen’s source location. Beamforming with modified steering vectors is performed to measure the parameters of the wavepacket source model from the far field. This process suggested replacing the wavepacket spatial length parameter with a temporal lifetime parameter. Another steering vector modification aimed to measure modes with odd spinning order. It seems to have found them at an apparent location 10 jet diameters removed from the jet, laterally. This is tentatively interpreted as a Mach radius phenomenon like one observed by Csaba Horvath at NASA-Glenn, also using Array 48, to study counter-rotating propeller noise. In an observation unrelated to beamforming, the excess noise measured at 40° from the jet axis as compared with the 90° angle, is fully contained in the first few cross spectral matrix eigenvalues, or Spectral Proper Orthogonal Decomposition modes, in some cases.

Impact of alkaloids extract of Moringa olievera Lam. leaves on the development, fertility and demography of the southern cowpea beetle insect Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

The Southern Cowpea Beetle Callosobruchus maculatus (F.) is one of the most widespread insect pests of stored legumes, causing a considerable loss during storage, decreasing the net weight of the crops, and resulting in reduced the quality of the crops. This study has been conducted to determine the lifetime, fertility and life table parameters of C. maculatus by using an alkaloids extract from Moringa oleifera leaves at different concentrations 1000, 2000, and 3000 ppm. The result was shown that the lowest survival rate was 49% at a concentration of 1000, 2000 ppm, as compared with the control which was 77%. The lowest reproductive rate (Ro) was 4.76 female/female/generation at the concentration of 1000 ppm, compared with the control which was 10.34 female/ female /generation while the lowest rate of egg hatching was 62% at the concentration of 3000 ppm as compared with the control 88%. Similarly, the sex ratio of male: to female was decreased after the use of the three concentrations, mostly at the concentration of 1000 ppm, in which the ratio was 1.31:0.69 compared to 1.11:0.89 for the control. Overall, the life tables curve shows that the survival rate, the ratio of the females and the productivity was affected in a negative way causing a decline in the whole insect population. It is clear from the above that the alkaloids extract of the leaves of the Moringa plant is effective and has an impact on the insect population, and can be an eco-friendly method of controlling on pest population.

Fatigue Threshold R-Curves for Dental Lithium Disilicate Glass–Ceramics

Chemical and mechanical fatigue degradation in ceramic materials is generally inconspicuous yet ubiquitous, to the effect that clinical fractures still consist of the main cause of failure in all-ceramic restorations. Implications of this span wide, from a reduced survival prognosis for the affected teeth, including more frequent and increasingly invasive procedural interventions, to the financial burden borne by individuals and health care systems. To suffice as an effective corrective, restoration lifetimes need only to be extended so to outlive the patient. That opens a box of problems from a materials science standpoint, entailing inherent deficiencies of brittle materials to resist mechanical and environmental challenges. Efforts in developing more damage-tolerant and fatigue-resistant restoratives go thus hand in hand with understanding intrinsic mechanisms of crack growth behavior under conditions that simulate the oral environment. Here we developed experiments using size-relevant sharp precracked specimens with controlled size and geometry (truncated semielliptical crack in the surface-crack-in-biaxial-flexure method) to establish a relationship between crack size and strength. The tangent method was used to construct envelopes for the quasi-static resistance curves (R-curves), which served as template for deriving residual cyclic R-curve analogs. By means of experimentally obtained stress–cycle curves, lifetime and fatigue parameters were employed within a mechanistic framework to reveal constitutive toughening mechanisms during subcritical growth under cyclic loading in a wet environment. Using 3 modern dental lithium disilicate glass–ceramics, we demonstrate the extent of R-curve degradation up to a threshold of 10 million cycles (~30 y in service) and draw parallels between the scope of fatigue degradation and the size of the microstructural units responsible for toughening mechanisms in glass–ceramic materials. Our results indicate that larger microstructural elements endow glass–ceramics with a higher reaching quasi-static R-curve at the onset but degrading more rapidly to comparable levels of lithium disilicates having submicrometric and nanometric crystal phases.

Nanostructure analysis and dielectric properties of PVA/sPTA proton exchange membrane for fuel cell applications: Positron lifetime study

Proton exchange membranes made of cross-linked polyvinyl alcohol and sulfophthalic acid (PVA-sPTA) were successfully fabricated by casting method and crosslinked at 100 °C with sPTA concentrations ranging from 10 to 30 wt%. TGA studies proved that the thermal stability of the crosslinked membranes was enhanced with increasing sPTA content. A Conventional fast–fast coincidence spectrometer was used to measure the RT positron annihilation lifetime parameters as a function of temperature. Proton conductivity was studied as a function of temperature and frequency. Ortho-positronium lifetime o-Ps, τ3 and the intensity I3 were found to decrease with increasing sPTA content as well. The glass transition temperature, determined from the positron annihilation lifetime temperature studies, was increased with increasing sPTA content. ε/ and ε// were increased with sPTA content. The binding energy of the charge carriers Wm decreased with increasing temperature which points out that the predominant conduction mechanism is the correlated barrier hopping.

A Comparative Parametric Study on Dynamic Biogenic Carbon of Harvested Wood Products: Biomass Rotation Period vs. Product Lifetime

Harvested wood products (HWPs) are a class of products that are recognized for their potential to mitigate climate warming: the absorption of CO2, which is necessary to the growth of their biomass feedstock, temporarily reduces the amount of CO2 present in the Earth’s atmosphere, effectively mitigating global warming. This study decided to look into the effect of changing two important parameters associated with HWPs: the rotation period of the biomass used for their raw material (effectively, the rate of CO2 absorption), and the length of their lifetime (effectively, the amount of time the captured carbon is stored within them in the form of embodied carbon). For this purpose, a carbon accounting calculator, Quantis’ Biogenic Carbon Footprint Calculator for Harvested Wood Products (BCFC-HWP), was employed. The Biogenic Global Warming Potential (GWPbio) metric, which was used by the BCFC-HWP to describe the climate impact of a wooden product’s embodied carbon, was analyzed for its evolution with respect to the two identified parameters. The results showed that while GWPbio followed a consistent decrease with respect to the product lifetime parameter, it showed a non-consistently evolving trend with respect to biomass rotation period i.e. first decreasing then increasing. This made the confrontation of both parameters’ effect complex mathematically, such that no clear-cut conclusions on the relative benefits of changing one parameter versus the other were made. Nonetheless, a valuable resolution was made based on the observations regarding the evolution of GWPbio with respect to the lifetime of an HWP: the results indicated that extending the lifetime of an HWP is an advantageous strategy in decreasing the climate effect of the considered product.

Influence of Thermal Maturity on the Time-Resolved Emission Spectrum (TRES) Fluorescence Lifetime Characteristics of Crude Oils: A Preliminary Study Based on a Thermal Simulation Experiment of Crude Oils

The time-resolved emission spectrum (TRES) fluorescence lifetime characteristics of crude oil have great application potential to classify the oil type and reveal its origin in a multisource petroleum system. However, the influence of thermal maturity on the TRES fluorescence lifetime characteristics of crude oil is still unclear. This study collected typical crude oil samples from deep reservoirs in the Tabei area of the Tarim Basin and obtained a group of pyrolyzed oils with different maturities by a thermal simulation experiment. The TRES average fluorescence lifetime value (τA) and profile pattern (λ–τ) of both pyrolyzed and crude oil samples were investigated. The results indicate that, with increasing maturity, the τA values of pyrolyzed oil slightly increase when EasyRo < 0.90% but decrease when EasyRo > 0.90%. Meanwhile, the λ–τ pattern shows no obvious changes when EasyRo < 1.53% but changes significantly when EasyRo > 1.53%. Based on the TRES fluorescence lifetime characteristics, the deep crude oils in various blocks of the Tabei area are divided into TB-I and TB-II types, which correspond well with their physical properties, diagnostic biomarkers, and carbon isotopic values. The TB-I crude oils are widely distributed in the Shunbei, Hadexun, Repu, and Halahatang blocks. This type of crude oil has a short τA value and exhibits an obvious platform pattern in its λ–τ profile. The TB-II crude oils are distributed only in the Yuke block. This type of crude oil has a long τA value and shows a unimodal pattern in its λ–τ profile. The TRES fluorescence lifetime parameters can effectively classify crude oils with different sources and can further identify the thermal maturity of crude oils with the same sources by combining them with the physical and geochemical parameters of crude oils, which exhibits great application potential to crude oils and individual petroleum inclusions in deep multisource petroleum systems.

5-Deazaalloxazine as photosensitizer of singlet oxygen and potential redox-sensitive agent

Flavins are a unique class of compounds that combine the features of singlet oxygen generators and redox-dependent fluorophores. From a broad family of flavin derivatives, deazaalloxazines are significantly underdeveloped from the point of view of photophysical properties. Herein, we report photophysics of 5-deazaalloxazine (1a) in water, acetonitrile, and some other solvents. In particular, triplet excited states of 1a in water and in acetonitrile were investigated using ultraviolet–visible (UV–Vis) transient absorption spectroscopy. The measured triplet lifetimes for 1a were all on the microsecond time scale (≈ 60 μs) in deoxygenated solutions. The quantum yield of S1 → T1 intersystem crossing for 1a in water was 0.43 based on T1 energy transfer from 1a to indicaxanthin (5) acting as acceptor and on comparative actinometric measurements using benzophenone (6). 1a was an efficient photosensitizer for singlet oxygen in aerated solutions, with quantum yields of singlet oxygen in methanol of about 0.76, compared to acetonitrile ~ 0.74, dichloromethane ~ 0.64 and 1,2-dichloroethane ~ 0.54. Significantly lower singlet oxygen quantum yields were obtained in water and deuterated water (ФΔ ~ 0.42 and 0.44, respectively). Human red blood cells (RBC) were used as a cell model to study the antioxidant capacity in vitro and cytotoxic activity of 1a. Fluorescence-lifetime imaging microscopy (FLIM) data were analyzed by fluorescence lifetime parameters and distribution for different parts of the emission spectrum. Comparison of multidimensional fluorescent properties of RBC under physiological-like and oxidative-stress conditions in the presence and absence of 1a suggests its dual activity as probe and singlet-oxygen generator and opens up a pathway for using FLIM to analyze complex intracellular behavior of flavin-like compounds. These new data on structure–property relationship contribute to the body of information required for a rational design of flavin-based tools for future biological and biochemical applications.Graphical abstract

Study of 405 nm Laser-Induced Time-Resolved Photoluminescence Spectroscopy on Spinel and Alexandrite

Research on photoluminescence spectroscopy on Cr-doped gem materials has demonstrated great success regarding the identification of gemstones in terms of building rapid test systems. In this study, 405 nm photoluminescence spectroscopy was used to measure the luminescence decay profiles of dozens of natural and lab-grown spinel (including heated spinel) and alexandrite. Spinel and alexandrite are both capable of producing photoluminescence with a long lifetime: spinel between 9 and 23 microseconds and alexandrite from 25 to 53 microseconds. The photoluminescence lifetime and exponential parameters of the half-life demonstrated notable differences in the ranges of decay times between natural, heated, and lab-grown versions of these materials.

An Intelligent Data Fusion Technique for Improving the Data Transmission Rate in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are made up of multiple source-restricted wireless sensor nodes that gather, process, and transmit information. Existing research work proposed energy competence with trust as well as Quality of Service (QoS) multipath routing protocol for improving network lifetime and other QoS parameters, selection criteria for multipath. However, this protocol has some limitations, such as scalability, data redundancy, bandwidth utilization, and network traffic. The most important challenge lies in managing the voluminous data produced by the network’s sensors. As a result of this study, Intelligent Data Fusion Techniques (IDFTs) were presented, which can greatly minimize redundant data, decrease the quantity of transmitting data, broaden the network life cycle, enhance bandwidth utilization, and therefore, resolve the energy and bandwidth usage bottleneck. This paper proposes Improved Whale Optimization Algorithms (IWOAs) for intelligent data fusion where the amount of data collected from sensor sources is reduced and the information offered is enhanced by duplicate data, which also increases data dependability. IWOAs are used to combine the actual information from the cluster’s sensor nodes at the sink node, resulting in increased information and the ability to make local judgments about the particular events. The sink node transmits local decisions to base station on a regular basis that combines the local decisions and provides the ultimate judgment, easing the pressure on the base station to evaluate all of the data. As per the results obtained, the proposed intelligent data fusion method significantly increases the network’s robustness and accuracy.

Energy-aware wireless mesh network deployment using optimization mechanism

Wireless mesh networks are widely used to create network infrastructure in rural areas due to their flexible properties, such as self-healing mechanisms and associated redundant paths. For example, a wireless mesh network can suitably operate with limited battery power in wildlife monitoring applications. The locations of mobile routers to support mobile sensor nodes are essential for extending the system lifetime. This study proposes an energy-aware wireless mesh network deployment optimization mechanism. The goal is to determine a suitable location for the mesh routers with the aim of maximizing network lifetime. After the location solution is obtained from the proposed mechanism, it is then evaluated for system lifetime and network performance by the network simulator (ns-3). The proposed method outperforms the brute-force method in terms of computation time for all amounts of mesh clients. For example, for 30 mesh clients, the proposed method uses only a few minutes, while the brute-force mechanism requires more than 200 minutes to complete the process. Furthermore, compared to the brute-force method, it achieves nearly the same system lifetime and other performance parameters, such as throughput, packet delivery ratio, and packet inter-arrival time. In the real implementation, in which the sensor node placements can be changed during the installation period owing to the environmental status or the recommendation of the installers, the results can be recalculated in a short period.